Nullable fields, and how to manage them (using sql.NullString)

[cajund]

Perhaps someone can help me out and point to what I am doing wrong.

I have a string field in a DB, it can be null, and setting it to null seemed to work when I was using a *string type. I have a record which has a value in the field, and I want to set it back to null. So, I switched to using sql.NullString. Per everything I can find on the Internet. This seems necessary as GORM will not include a field if the value is not null.

Now, when I want to change the value in the record this back to null, GORM isn't adding the field to the generated SQL:

Struct with the fields:

type Alias struct {
	ID         string `gorm:"primaryKey"`
	FacilityId string
	LinkId     string
	SchemeId   sql.NullString
	Alias      string
	CreatedAt  time.Time
	UpdatedAt  time.Time
}

Populated struct to use for .Updates()

{ID: FacilityId: LinkId: SchemeId:{String: Valid:false} Alias:SOMEALIAS CreatedAt:0001-01-01 00:00:00 +0000 UTC UpdatedAt:0001-01-01 00:00:00 +0000 UTC} 

Generated SQL

UPDATE `aliases` SET `alias`='WWALIAS',`updated_at`='2024-10-07 23:44:18.447' WHERE id = 'd0a0d9e0-ed47-4ed0-b146-6620e18b0566' and facility_id = '227f1c44-6ed7-41a1-9ee7-3b8bdbd8cf66' 

Note the absence of the SchemeId (scheme_id) in the SQL. It clearly has a non-nil type, but I can't seem to see how to accomplish this.

And I would like to avoid pulling, then saving the record.

Thanks.